Removal of disabilities is what emancipation is called in Texas.
You must be 16 or 17 to even apply for it. AND judges usually won't grant it unless you are able to 100% support yourself without anyone else's assistance.
I find that most attorneys won't help a minor seek emancipation without at least $5,000 on account plus all fees (filing fee is approx. $300) since it is not easy and there is a lot of work to be done to prove that a child is able to 100% support themselves without help from anyone. I find that only athletes and entertainers qualify - they need to be able to sign endorsement contracts. I don't see the regular teenager convince a judge to sign unless both parents agree to this lawsuit. And normally you still need a good reason for a judge to make you an adult.
Chapter 31 of the Texas Family Code covers "Removal of Disabilities of Minority".
It goes into detail under Section 31.002 of the minimum required info that the Petition must contain.
Section 31.004 requires the judge to appoint an amicus attorney or attorney ad litem to represent the interests of the petitioner (the child) at the hearing. You pay for this attorney and it normally costs at least $750 and can go up to $5,000 depending on their hourly rate and how much work they have to do.
Even if you are emancipated no one HAS to lease to you or sell you a car with a note. You probably won't have any credit established in your name if you are 16 or 17. Therefore, most companies won't extend you a line of credit or lease to you until you have a credit score.
Emancipating is not "magical".